Description: (Applicant's Description) The Crystallography Facility offers the capability for determination of the crystal structure of small molecules (e.g., peptides or ligands), as well as macromolecules (i.e., proteins or nucleic acids). Crystals produced by individual research groups are tested for diffraction and analyzed for the extent of diffraction resolution. X-ray diffraction data are collected by diffractometer measurements for small molecules and by multiwire area detectors or imaging plate detectors for macromolecules. The crystallographers affiliated with the Crystallography Facility interact directly with users to devise strategies to determine the crystal structures of interesting molecules. This information is critical to the ongoing research of a number of Institute projects.